Multiple Choice QuestionsGiven below are a few statements on Agrobacterium mediated transformation of plants. Which one of the following statements is CORRECT?
T-DNA transfer occurs from left border to right border
The gfp reporter gene can never be used for selection of transgenic plants
Transformation frequencies will decrease on overexpression of virulence genes.
Which one of the following assay systems can specifically detect apoptotic cells?
Tetrazolium dye (MTT) based colorimetric assay
FITC – annexin V based FACS analysis
51Cr release assay
From the various techniques listed below, which one CANNOT be used to precisely map the transcription start-site of a gene?
S1 Mapping
Sequencing the region downstream of promoter
5’ RACE
Primer Extension Method
A group of scientists performed an experiment where they artificially fused mouse cells with monkey cells. The resulting fused cells were labelled with fluorescently tagged antibodies against mouse and monkey surface receptor proteins, X and Y respectively. At the time 0 minute just after fusion events, two receptors were confined to their own half in the heterokaryon. However, such surface receptors (X and Y) intermixed on the cell surface after 60 minutes. Which one of the given statements correctly reflects the outcome of the experiment?
The ptoteins in cytoplasm are in a dynamic state.
The proteins on the membrane surface are in a dynamic state.
Surface membrane proteins exchange with the cytosolic proteins.
Membrane surface proteins are in a static phase.
B.
The proteins on the membrane surface are in a dynamic state.
The fluorescent tags are attached to surface receptors X and Y, on mouse and monkey cells respectively. After fusion both the tags remain on the surface and are not lost with time. Only with time they change thier position. This shows that membrane proteins are not static but dynamic. Since the tags are not lost with time so, they surface proteins are not exchanged with the cytoplasmic protein. Since the tags are specific so for surface proteins so no conclusion about the cytoplasmic proteins can be drawn for this experiment.
In order to detect minor variations in antigen concentration, the following procedures were suggested. Which one will likely be the best option?
Antigen coated microtitre well → add antibody → add enzyme conjugated secondary antibody → add substrate and measure colour.
Antibody coated microtitre well → add antigen →add enzyme conjugated secondary antibody → add substrate and measure colour.
Preincubate antigen with fixed amount of antibody → add to antigen coated well → add enzyme conjugated secondary antibody → add substrate and measure colour.
Preincubate antigen with fixed amount of antibody → add to antibody coated well →add enzyme conjugated secondary antibody → add substrate and measure colour.
(i), (ii) and (iii)
(i), (ii) and (iv)
(i), (iii) and (iv)
(ii), (iii) and (iv)
use of fluorescent probes specific for organelles.
use of organelle specific fluorescent probes followed by microinjection of fluorescent antibodies against organelle specific protein.
use of fluorescent probes in permeabilized cells.
use of organelle specific fluorescent probes followed by cryoelectron microscopy
(a), (b), (c)
(a), (c), (d)
(b), (d)
(c), (d)
(a), (b), (e), (f), (g)
(a), (b), (c), (d), (g)
(a), (d), (e), (f), (g)
(c), (d), (e), (f), (g)
Which one of the following set of essential components are required for Sanger method of DNA sequencing in a required buffer containing MgCl2 and Tris-HCl?
DNA template, a primer, 4 deoxyribonucleotides, 4 labelled dideoxyribonucleotides, DNA polymerase
DNA template, a primer, 4 labelled dideoxyribonucleotides, DNA polymerase, DNA ligase
DNA template, 4 deoxyribonucleotides, 4 labelled dideoxyribonucleotides, DNA polymerase, DNA ligase.
DNA template, a primer, 4 labelled dideoxyribonucleotides, DNA polymerase, telomerase.
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